Heat-treating furnace



R. E. BROCK AND S. BYCE.

HEAT TREATiNG FURNACE.

APPLlcATmN FILED SEPLG, 1919.

3 SHEETS-SHEET l.

1 $36,814. atente Apr. 13, 1920.

R. E. BROCK AND S. BOYCE.

HEAT TRI-:Amma FuRNAcE.

' APFLlCATION FILED SEPT. 6| 1919. l 1,336,814, l Patented. Apr.. 139 192 3 SHEETS--SHEET Z.

R. E. BROCK AND S. BOYCE.

HEAT TREATING FURNACE.

APPLICATION FILED SEPLG, 1919.

1,3363 1 4. Patented Apr. 13, 1920.

3 SHEETS-SHEET 3.

RICHARD E. BROCK AND STANLEY BOYCE, OF CANTON, OHIO.

HEAT-TREATING FURNACE.

Specification of Letters Patent.

Patented Apr. 13, 1920.

Application filed September 6, 1919. Serial No. 322,189.

To all whom t may concern.'

Be it known that we, RICHARD E. BROCK and STANLEY Boron, citizens of-the United States, residing at Canton, in the county of tark and State of Ohio, have invented a new and useful Heat-Treating Furnace, of which the following is a specification.

Our invention relates to improved furnaces for carbonizing and case-hardening or heat treating steel parts.

The principal object of our invention is to provide improved means whereby steel parts may be carbonized more uniformly than by the means heretofore employed, and a greater depth of carbonizing obtained in shorter time and at lessr cost. Generally stated, our furnace consists of a heat chamber having a rotary container mounted therein and constructed preferably with internal spiral case so arranged that 'the material therein to be treated will travel to all parts of the furnace and with constant agitation in the operation; and', furthermore, providing by the same device speedy and convenient ways of charging and discharging the furnace, whereby the loss of heat while emptying and relling the furnace is very materially reduced. In connection therewith improved means are also provided for delivering, separating and conveying therefrom the parts after heat treatment-all as hereinafter fully set forth and as stated in the appended claims.

Our invention isy illustrated by the accompanying drawings in which similar letters and gures of reference indicate like parts.

Referring to the drawings, Figure l is a top or plan view of a furnace embodying our invention, the container and other interior parts being indicated byvdotte'd lines; Fig. 2 is a' vertical longitudinal' cross section of Fig. 1 on the dotted line 1 1; Fig. 3 is a vertical transverse section of Fig. 1 onthe dotted line 2-2; Fig. 11 is a top or plan view of the container operati-ve mechanism; Fig. 5 is a vertical transverse section of Fig. 4c on the dotted line 3 3; and Fig. 6 is a detail end view of adjacent operative parts of Fig. 4.

In the drawings, A is the top of the furnace, B' the rear end wall, C the front end opening, D the bottom, and D a chute sloping downwardly at the front end of the bottom; E is the container; F and G are end views of receptacles or traveling conveyers,

thereby said supporting rolls of each as the case may be, and H is a screen chute leading outwardly from the chute D. These constitute the principal parts of our improved furnace, and are best shown in Fig.

2. The furnace walls are constructed in the said supports being secured in any desired adjustment by means of a set screw 5, and

pair are made to approach each other underneath the container, substantially as shown in -Fig 3.

The front pair of rolls are so mounted as to travel in a peripheral channel 6 which secures the container against endwise movement within the heat chamber of the furnace. It is apparent that the container may be thus adjusted either laterally or longitudinally to any desired position for rotation upon said pairs of supporting rolls.

The container is closed at its rear end and open at its front end, and provision is made for closing and sealing the latter end by means of a head 7 provided with asbestos or other suitable gasket 8 to abut against the marginal edge 9 of the container, as shown in Fig. 2.

The head 7 is attached to the door C of the furnace and is adjustable theretoby thc hand wheel 1 0 in connection with the threaded shaft 11 and coiled spring 12 and its abutment 13 mounted on the tube 14 by the set screw 15. The spring 12 allows for the natural expansion of the container due to change of heat of the furnace. The hand wheel and its gear are supported at a suitable distance from the furnace walls by the frame 1G which is secured to the metal covering of the door C by bolts 16'; and said door swings outwardly on hinges attached to said covering and front wall of the furnace. Only one of said hinges is shown, 17, as it suliices for illustration.

The metal tube 14 projects outwardly from and through the center of the head 7 to a point beyond the hand wheel 10 and is provided with a stop-cock 18 at its outer end, which controls the opening through the stem veo of the tube, and, when open, permits the eX- hausting of the gases and relieves the pressure which accumulates in the container from the gases arising from the bone black or other carbonizing material, or from oil on the parts which are being treated. Said gases can be kept at a predetermined pressure within the container by the substitution of a safety or pop valve set at the desired pressure, instead of the stop-cock 18. This tube also provides opportunity for pyrometer observation, at pleasure.

The tube is sealed in its passage through the door cover by a threaded collarlt), which prevents heat escaping from the furnace when the door thereof is shut.

The container, mounted on said rolls as aforesaid, is rotated by means of a jaw clutch 20 and shaft 21 at its rear end, the latter being actuated through worm gear mechanism as shown in Figs. Ll and or other suitable rotating mechanism, equipped with `reversing attachments to reverse the rotation of the container periodically, if desired.

As a preferred means of accomplishing such rotation this mechanism is designed so ,that the container rotates in one direction until the spiral groove 22 on its inner periphery carries the material, which is being treated within 1t, to one end of the furnace,

-when the direction of rotation is reversed and the material returned to the other end; and this process is repeated until the time limit for such treatment expires. Our said preferred power and reversing mechanism is mounted upon a supporting frame 23, which is fixed upon an extension of the furnace bed plates 23', and power is derived from shaft pulleys 24, which actuate the main belt wheels 24 in the usual and well known way; a worm 25 on the belt driven shaft 26 actuates the worm wheel 27, which is mounted on the extension 28 of the container shaft 21 within the framework 29, and is controlled by the counter shaft clutch 30.

The shaft extension 2S terminates with a threaded member 31 on which is mounted a traveling pinion 32 which operates the shift-reversing rack 32 and belt shifting arms 33 and Se, and is surmounted with a collar 35 for timing the reversal secured adjustably by the set screw 86. A sealing eollar 37 surrounds the shaft 21 at its intersection with the wall of the furnace to prevent escape of heat at this point. T he threaded shaft 11, actuated by the hand wheel 10, is bored to provide a suitable bearing 38 for the tube let and is operable upon the thrustball race 39. The conveyer G operable in the trench 40 afford means for oil bath, or other suitable means for suddenly cooling the articles as they pass out of the furnace and before they lose the heat acquired therein, and then delivering the same elsewhere as may be desired. The screen chute H in connection with the receptacle or conveyer, as the case may be', affords convenient means for separating the f heat treated materials from thecarbonizing and other waste materials when the container is emptied; and this emptying is readily accomplished by opening the door and thereby withdrawing the sealed head 7, and continuing the rotation of the container in forward direction until the spiral groove has carried all material therein beyond the open end of the container and deposited it upon the chute D, whence it is delivered by gravity into receptacles as aforesaid.

@ther equivalent means may be employed to rotate the container, and to reverse the direction of its rotation at predetermined intervals, and to time the operation, without departing from the scope of our invention.

By the means aforesaid, or equivalent means, the steel parts being treated within the container are kept constantly moving from one end of the furnace to the other thereby equalizing the heat thereon, and are furthermore kept in constant agitation together with the carbonizing materials so that all surfaces of the steel parts are kept in equal contact therewith, and a uniform depth of carbonizing is thereby obtained.

We do not limit ourselves to the particular form, proportion or other details, and the same may be modified to accomplish the objects of our invention without departing therefrom and within its scope, and our 100 furnace may be used not only for carbonizing but for annealing vor any other heat treatment of metal parts, when in the process they are to be heated, either with or without being in contact with carbonizing ma- 105 terials.

lVe are aware it is not new to provide a vent tube for the escape of gases from a furnace for annealing metal, and for pyrometric observation; and also that retorts have been 110 heretofore constructed to rotate within a furnace; and that drums have been constructed with spirally arranged conveyers therein, and such we do not broadly claim.

Having thus fully described our inven- 115 "tion, what we claim as new and desire to serotating said container in opposite directions periodically; and means for receiving 15 and conveying treated parts and Waste materials from said furnace automatically, substantially as set forth.

In Witness whereof, We hereunto set our hands this 6th day of June, 1919.

RICHARD E. BROOK. STANLEY BOYCE.

In presence of two Witnesses:

JOHN D. BAsr, DAVE T. LYsAGi-rr. 

